I would wonder if the instructor who trained this pilot was ever aware of his tendencies to “rivet” his attention to one particular reference … apparently to the exclusion of all the others that should remain an active part of his scan?
The FO said the PAPI was his
primary reference during approach; he did not say it was his
only reference. He stated that his crosschecks were the PAPI, the runway, and the airspeed. He said he also referred the glideslope every 3 to 4 crosschecks. (Ref: NTSB Interview Summaries, pp. 17-18).
The FO was an instructor himself, w/ 22 years in the USAF flying F-15C and F-117s. He was a T-38 chief evaluator until he retired and joined SWA. At the time of the accident he had 1,200 hrs at SWA.
People make mistakes; One would hope someone with his flight experience has the basics of flying (and landing) down pat.